CN118929646A

CN118929646A - Dispersion containing graphene carbon nanoparticles and dispersant resin

Info

Publication number: CN118929646A
Application number: CN202411141340.6A
Authority: CN
Inventors: Q·丁; M·J·鲍里克; C·B·内迪格; C·卡捷克; L·J·拉法纳; M·W·斯金纳; J·G·维斯; I·Y·冈萨雷斯; H·W·罗; S·L·艾萨雷; P·M·克里斯
Original assignee: PPG Industries Ohio Inc
Current assignee: PPG Industries Ohio Inc
Priority date: 2019-02-20
Filing date: 2020-02-19
Publication date: 2024-11-12
Also published as: KR102616754B1; CA3130338C; MX2021010070A; CN113454022B; US12084349B2; JP2024015343A; CN113454022A; KR20210114514A; US20220127145A1; BR112021016482A2; AU2020224116B2; US20240425375A1; WO2020172330A1; MX2025009455A; CA3130338A1; AU2020224116A1; JP2022521587A; EP3927660A1; JP7447135B2

Abstract

Disclosed are graphene carbon nanoparticles dispersed in a solvent using a dispersant resin. The graphene carbon nanoparticles may be ground before dispersion. The dispersant resin may include a polymer dispersant resin, which includes an addition polymer containing a vinyl heterocyclic amide residue, a homopolymer, a block (co)polymer, a random (co)polymer, an alternating (co)polymer, a graft (co)polymer, a brush (co)polymer, a star (co)polymer, a telechelic (co)polymer or an addition polymer of a combination thereof. The solvent may be an aqueous, non-aqueous, inorganic and/or organic solvent. The dispersion is highly stable and may contain a relatively high loading of the graphene carbon nanoparticles.

Description

Dispersion containing grapheme carbon nanoparticles and dispersant resin

The application is a divisional application of a Chinese patent application with the application number 202080015403.7.

Cross Reference to Related Applications

The present application claims the preference of U.S. provisional patent application No. 62/808,126 filed on 2 months 20 in 2019, which is incorporated herein by reference.

Technical Field

The present invention relates to dispersions containing grapheme carbon particles and a dispersant resin, and more particularly to dispersions of ground grapheme carbon particles and a dispersant resin in an aqueous solvent and/or an organic solvent.

Background

Graphene nanoparticles have many current and potential uses. However, such nanoparticles may be difficult to disperse in other materials.

Disclosure of Invention

The present invention provides a dispersion comprising a solvent, grapheme carbon nanoparticles having an average aspect ratio greater than 3:1 and a raman 2d to g peak ratio of at least 1:1, and a polymeric dispersant resin comprising an addition polymer comprising vinyl heterocyclic amide residues.

The invention also provides a dispersion comprising an organic solvent, grapheme carbon nanoparticles, a polymeric dispersant resin comprising an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer.

The present invention also provides a method of dispersing grapheme carbon nanoparticles in a solvent comprising mixing a dispersant resin into the solvent, wherein the dispersant resin comprises an addition polymer comprising vinyl heterocyclic amide residues, an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer, or a combination thereof; and mixing the grapheme carbon nanoparticles into a solvent and dispersant resin mixture.

Drawings

Fig. 1 is a graph of instability index of an oil dispersion containing milled plasmonic carbon particles and milled exfoliated grapheme carbon versus time.

Fig. 2 is a graph of instability index versus time for an aqueous dispersion containing milled plasmonic carbon particles and milled exfoliated graphenic carbon particles.

Fig. 3 is a photograph of a dried graphene carbon nanoparticle dispersion showing a more uniform particle dispersion of milled graphene carbon nanoparticles relative to unground graphene carbon nanoparticles.

Fig. 4 and 5 are photomicrographs and corresponding line graphs showing non-uniform size of aggregated grapheme carbon nanoparticles produced from an unground grapheme carbon nanoparticle dispersion.

Fig. 6 and 7 are photographs and corresponding line graphs showing uniformly dispersed non-aggregated grapheme carbon nanoparticles of uniform size produced from a milled grapheme carbon nanoparticle dispersion.

Fig. 8 is a graph of oxygen content versus milling time for graphene carbon nanoparticle samples.

Fig. 9 is a graph of defect levels versus milling time for graphene carbon nanoparticle samples.

Fig. 10 and 11 are TEM images of unground grapheme carbon nanoparticles and ground grapheme carbon nanoparticles, respectively.

Fig. 12-14 are dynamic frequency sweep results showing storage modulus (G'), loss modulus (G "), and complex viscosity, respectively, of unground grapheme carbon nanoparticle dispersions containing different loadings.

Fig. 15-17 are dynamic frequency sweep results showing the storage modulus (G'), loss modulus (G "), and complex viscosity of milled grapheme carbon nanoparticle dispersions containing different loadings, respectively.

Fig. 18 includes a plot of viscosity versus shear rate for an aqueous grapheme carbon nanoparticle dispersion containing 8 wt% unground grapheme carbon nanoparticles versus 20 wt% milled grapheme carbon nanoparticles.

Fig. 19 shows the viscosity of an aqueous graphene carbon nanoparticle dispersion at a shear rate of 10Hz for a dispersion containing 8 wt% unground graphene carbon nanoparticles relative to a dispersion containing 20 wt% milled graphene carbon nanoparticles.

Fig. 20 includes a plot of viscosity versus shear rate for a grapheme carbon nanoparticle dispersion in an organic solvent containing 5 wt% unground grapheme carbon nanoparticles, 10 wt% milled grapheme carbon nanoparticles, and 15 wt% grapheme carbon nanoparticles.

Fig. 21 shows the viscosity of a grapheme carbon nanoparticle dispersion in an organic solvent containing 5 wt.% unground grapheme carbon nanoparticles, 10 wt.% ground grapheme carbon nanoparticles, and 15 wt.% grapheme carbon nanoparticles at a shear rate of 10 Hz.

Fig. 22-24 are graphs of instability index of dispersions containing milled graphene carbon nanoparticle dispersions and unground graphene carbon nanoparticle dispersions versus time.

Figure 25 shows the instability index values of graphene nanoparticle dispersions in different types of organic solvents including N-methyl-2-pyrrolidone (NMP), SAR acrylic resin, and copolymers of lauryl methacrylate and vinyl pyrrolidone with different LMA content (LMA-VP).

FIG. 26 shows the viscosity of grapheme carbon nanoparticle dispersions at 10Hz shear rate in PVP of LMA-VP dispersant resin with increased lauryl methacrylate content.

FIG. 27 shows the viscosity of grapheme carbon nanoparticle dispersions at 10Hz shear rate in PVP of LMA-VP dispersant resin with increased lauryl methacrylate content.

FIG. 28 shows the viscosity of grapheme carbon nanoparticle dispersions at 10Hz shear rate in PVP of LMA-VP dispersant resin with increased lauryl methacrylate content.

FIG. 29 is a plot of D50 particle size versus lauryl methacrylate content in the slurry as a weight percent of total solids in the slurry.

FIG. 30 is a plot of viscosity and D50 particle size versus lauryl methacrylate content in the slurry as a weight percent of total solids in the slurry.

Fig. 31-38 are scanning electron microscope images of lithium ion cathode films prepared with graphene carbon nanoparticle dispersions.

Fig. 39 is a graph of capacity retention versus cycle number for lithium ion cathode membranes prepared with grapheme carbon nanoparticle dispersions at various C-rates.

Fig. 40 is a graph of capacity retention versus cycle number for lithium ion cathode membranes prepared with grapheme carbon nanoparticle dispersions at various C-rates.

Detailed Description

The present invention provides graphene carbon nanoparticle dispersions that are stable during storage and use. The stable dispersions can be used in a variety of different applications including conductive inks, battery anode and/or cathode coatings, supercapacitors, EMI shielding, RFI shielding, thermally conductive coatings, electrically conductive coatings, lubricants, coolants, composites, 3D printing, and the like. The conductive ink may include silver ink, medical electrode ink, silver hybrid ink, carbon ink, dielectric ink, zinc electrode cell ink, manganese cell ink, thermoset carbon cell ink, IR transparent anti-counterfeit ink, and low resistance UV ink. Applications for conductive inks include smart phones, tablet computers, interactive and electrochromic displays, biomedical sensors, printed keyboards, industrial membrane switch controls, RFID tags, and other products with printed circuitry.

As used herein, the term "dispersed" refers to grapheme carbon nanoparticles dispersed in a medium (such as a solvent containing a polymeric dispersant) to form a substantially uniform dispersion of grapheme carbon nanoparticles throughout the medium without substantial aggregation of the particles. As described more fully below, the uniformity of the dispersion can be measured by an "instability index". The presence of aggregation can be determined by standard methods, such as visual analysis of TEM microscopy images. Aggregation can also be detected by standard particle size measurement techniques as well as measurement of electrical conductivity or measurement of optical properties such as color, haze, blackness, reflectivity and transmission properties of materials containing grapheme carbon particles.

The grapheme carbon nanoparticles may be milled to improve their dispersibility and/or stability in the composition. Various different types of milling techniques may be used, such as solid state milling, ball milling, dry ball milling, eiger milling, LAU milling, cowles sharpening, and the like.

In addition to grapheme carbon nanoparticles, dispersions include various types of resin dispersants. The resin may increase the dispersibility and/or stability of the grapheme carbon nanoparticles in the dispersion. For example, the resin dispersant may include a combination of Lauryl Methacrylate (LMA) and Vinyl Pyrrolidone (VP) resins. LMA-VP copolymers can be synthesized using conventional free radical polymerization chemistry. In such formulations, LMA may typically comprise 10 to 90 wt% and VP may typically comprise 10 to 90 wt%. For example, the LMA may range from 40 or 50 to 85 wt%, while the VP may range from 15 to 50 or 60 wt%. In certain embodiments, LMA may comprise about 75 wt% and VP may comprise about 25 wt%. The resin dispersant may promote dispersion and stability in both milled and unground grapheme carbon nanoparticle dispersions.

For example, the resin dispersant may include an addition copolymer comprising Stearyl Acrylate (SA) and Vinylpyrrolidone (VP) residues. The SA-VP copolymer can be synthesized using conventional free radical polymerization chemistry. In such formulations, SA may typically comprise 10 to 90 wt% and VP may typically comprise 10 to 90 wt%. For example, SA may range from 40 or 50 to 85 wt%, while VP may range from 15 to 50 or 60 wt%. In some embodiments, SA may comprise about 75 wt% and VP may comprise about 25 wt%.

For example, the resin dispersant may include an addition polymer comprising a vinylpyrrolidone residue, such as, for example, polyvinylpyrrolidone (PVP). The PVP may have a weight average molecular weight of at least 1,000g/mol, such as at least 3,000g/mol, such as at least 5,000g/mol. The PVP may have a weight average molecular weight of no more than 2,000,000g/mol, such as no more than 1,000,000g/mol, such as no more than 500,000g/mol, such as no more than 100,000g/mol, such as no more than 50,000g/mol, such as no more than 20,000g/mol, such as no more than 15,000g/mol. The PVP may have a weight average molecular weight of 1,000 to 2,000,000g/mol, such as 1,000 to 1,000,000g/mol, such as 1,000 to 500,000g/mol, such as 1,000 to 100,000g/mol, such as 3,000 to 50,000g/mol, such as 5,000 to 20,000g/mol, such as 5,000 to 15,000g/mol.

The weight ratio of grapheme carbon nanoparticles to resin dispersant may generally be in the range of 0.1:1 to 20:1, for example 0.5:1 to 15:1, 1:1 to 10:1, or 3:1 to 6:1, such as 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

The dispersant resin enhances the dispersion stability of grapheme carbon nanoparticles and can expand the use of such nanoparticles in conductive inks, battery fabrication, thermally conductive coatings, EMI and RFI shielding coatings, lubricants, composites, 3D printing, and the like. The dispersants of the present invention may include the following advantages: prolonged shelf life, high grapheme carbon nanoparticle loading and stable dispersion at room temperature and elevated temperature.

The grapheme carbon nanoparticles and the resin dispersant can be added to various types of solvents to make the dispersions of the present invention. Suitable solvents include aqueous and organic solvents such as N-methyl-2-pyrrolidone (NMP), oils, benzyl alcohol, diethylene glycol monoethyl ester (DE) acetate, triethyl phosphate, and the like.

The grapheme carbon nanoparticles of the present invention can be dispersed in relatively large amounts in various types of aqueous and organic solvents to produce dispersions having relatively high grapheme carbon particle loadings compared to conventional grapheme carbon particle dispersions. For example, the milled grapheme carbon particles may comprise at least 5 weight percent of the total weight of solvent and grapheme carbon particles. For example, the milled grapheme carbon particles may comprise at least 8 wt.%, or at least 10 wt.%, or at least 12 wt.%, or at least 15 wt.% of the dispersion. For example, in an aqueous-based solvent dispersion, the milled grapheme carbon particles may be dispersed in an amount of up to 20 wt%, or up to 23 wt%, up to 25 wt%, or higher. In an organic solvent dispersion such as NMP, the milled grapheme carbon particles may be present in an amount of up to 10 wt.%, or up to 12 wt.%, or up to 15 wt.%, or up to 20 wt.% or more. Alternatively, the loading of the milled grapheme carbon particles may be relatively low, such as less than 5 or 3 weight percent, or less than 2 or 1 weight percent, or less than 0.5 or 0.1 weight percent.

Grapheme carbon nanoparticles can be added to the base formulation at relatively low loadings compared to conventional additives. For example, the grapheme carbon nanoparticle dispersions of the present invention can be added to a base formulation or material at a particle loading of less than 5 wt%, or less than 2 wt%, or less than 1 wt%, or less than 0.5 wt%, while meeting or exceeding the performance of conventional grapheme-containing formulations or materials. For example, a loading of 0.05 to 1 wt.% or 0.1 to 0.5 wt.% may be used in the lubricant formulation.

Instability index analysis can be used to accelerate the assessment of long term stability, which measures dispersion sedimentation at a specific centrifugal speed and temperature. Unless otherwise indicated in the specification or claims, the measurement of "instability index" is as follows: a dispersion sample was loaded into a centrifuge and 865nm pulsed near infrared light was transmitted through the sample. During centrifugation, near infrared light transmitted through the sample was measured using a dispersion analyzer sold under the name LUMiSizer Model 611 by LuM GmbH. The measurements were carried out at 25℃and 4000rpm centrifuge speed, with Relative Centrifugal Acceleration (RCA) of 2202 during 20 minutes of centrifugation. The transmission level at the beginning of centrifugation was compared to the transmission level at the end of the 20 minute period and the instability index was calculated by normalizing the recorded transmission level changes. The instability index reported is a dimensionless number between 0 and 1, where "0" indicates no change in particle concentration and "1" indicates that the dispersion has completely phase separated. Due to the significant phase separation of grapheme carbon nanoparticles and solvent, a relatively unstable dispersion will exhibit a higher increase in transmittance, while a relatively stable dispersion will exhibit a lower increase in transmittance due to less phase separation. Can be usedThe software tool calculates an instability index. The article entitled "instability index" (T.Detloff, T.Sobisch, D.Lerche, instability index, dispersion LETTERS TECHNICAL), T4 (2013) 1-4, update 2014)How the software tool determines the instability index is incorporated herein by reference. The instability index of the milled grapheme carbon nanoparticle aqueous dispersion can generally be less than 0.7, for example, less than 0.6, or less than 0.5, or less than 0.4, or less than 0.3, or less than 0.1. The instability index of the dispersion of the milled grapheme carbon nanoparticles in the oil solvent is typically less than 0.5, for example, less than 0.4, or less than 0.3, or less than 0.2, or less than 0.1.

The instability index may be at least 10% less, e.g., at least 50% less, or at least 100% less, or at least 300% less, or at least 500% less, than a similar dispersion containing unground grapheme carbon particles.

The solvent mixture containing milled grapheme carbon particles may have a lower viscosity than a similar solvent mixture containing unground grapheme carbon nanoparticles. For example, at a loading of 1 wt% grapheme carbon nanoparticles, the milled grapheme carbon particles may result in a solvent dispersion having a viscosity that is at least 10% or 20% lower than a similar solvent dispersion having unground grapheme carbon particles. Viscosity can be measured by standard techniques, where rheological measurements are collected using Anton Paar MCR 302 and CP50-1/TG measuring cone. Viscosity measurements at a shear rate of 10Hz can be used to compare the dispersion rheology.

The milled grapheme carbon nanoparticle dispersion may be added to a variety of base formulations, for example, by stirring, shaking, grinding, milling, and the like. As described above, the base formulation into which the grapheme carbon nanoparticle dispersion may be incorporated may include various types of inks, coatings, lubricants, and the like.

The grapheme carbon particles used in the present invention may be obtained from commercial sources, such as Raymor, angstron, XG Sciences, and other commercial sources. As discussed in detail below, grapheme carbon particles may be thermally produced according to the methods and apparatus described in U.S. patent nos. 8,486,363, 8,486,364, and 9,221,688, which are incorporated herein by reference. Carbon nanotubes or other carbonaceous materials such as conductive carbon black, graphite, and the like may be used in combination with or in place of the grapheme carbon particles.

As used herein, the term "graphenic carbon particles" refers to carbon particles having a structure comprising one or more layers of planar sheets of sp ² -bonded carbon atoms that are monoatomically thick, the carbon atoms being densely packed in a honeycomb lattice. The average number of stacked layers may be less than 100, for example less than 50. In certain embodiments, the average number of stacked layers is 30 or less, such as 20 or less, 10 or less, or in some cases 5 or less. The average number of stacked layers may be greater than 2, for example, greater than 3, or greater than 4. At least a portion of the grapheme carbon particles may be in the form of substantially curved, curled, creased or buckled platelets. The grapheme carbon nanoparticles may be turbine stationary, i.e., adjacent stacked atomic layers do not exhibit ordered AB Bernal stacks associated with conventional exfoliated graphenes, but rather exhibit unordered or non-ABABAB stacks. Or the grapheme carbon particles may be in the form of nanotubes. The particles generally do not have a spherical or equiaxed morphology.

The grapheme carbon nanoparticles may have a thickness, measured in a direction perpendicular to the carbon atom layer, of no greater than 10 nanometers, no greater than 5 nanometers, or in some embodiments no greater than 4 or 3 or 2 or 1 nanometers, such as no greater than 3.6 nanometers. The grapheme carbon particles may be from 1 atomic layer to 3, 6, 9, 12, 20, or 30 atomic layers thick or thicker. The grapheme carbon particles present in the compositions of the present invention have a width and length measured in a direction parallel to the carbon atom layer of at least 50 nanometers, such as greater than 100 nanometers, in some cases greater than 100 nanometers up to 500 nanometers, or greater than 100 nanometers up to 200 nanometers. The grapheme carbon particles may be provided in the form of ultrathin sheets, platelets, or sheets having a relatively high aspect ratio (aspect ratio is defined as the ratio of the longest dimension of the particle to the shortest dimension of the particle) of greater than 3:1, such as greater than 10:1. Or when the grapheme carbon particles are in the form of nanotubes, they may have an outer diameter of 0.3 to 100 nanometers, or 0.4 to 40 nanometers, a length of 0.3 nanometers to 50 centimeters, or 500 nanometers to 500 micrometers, and an aspect ratio of 1:1 to 100,000,000:1, or 10:1 to 10,000:1.

The grapheme carbon particles may have a relatively low oxygen content. For example, even when having a thickness of no greater than 5 nanometers or no greater than 2 nanometers, the grapheme carbon particles may have an oxygen content of no greater than 2 atomic weight percent, such as no greater than 1.5 or 1 atomic weight percent, or no greater than 0.6 atomic weight, such as about 0.5 atomic weight percent. The oxygen content of grapheme carbon particles can be determined using an X-ray photoelectron spectrometer, such as described in d.r. dreyer et al, review of the chemistry society (chem. Soc. Rev.) 39,228-240 (2010).

The grapheme carbon particles may have a b.e.t. specific surface area of at least 50 square meters per gram, such as from 70 to 1000 square meters per gram, or in some cases, from 200 to 1000 square meters per gram, or from 200 to 400 square meters per gram. As used herein, the term "b.e.t. specific surface area" refers to a specific surface area determined by nitrogen adsorption according to astm d 3663-78 based on The Journal of The american Society of chemistry, 60,309 (1938) method of Brunauer-Emmett-Teller.

The grapheme carbon particles may have a raman spectral 2D/G peak ratio of at least 0.9:1, or 0.95:1, or 1:1, such as at least 1.2:1 or 1.3:1. As used herein, the term "2D/G peak ratio" refers to the ratio of the 2D peak intensity at 2692cm ^-1 to the G peak intensity at 1,580cm ^-1. Such 2D/G peak ratios may be present in grapheme carbon nanoparticles having an average number of stacked layers greater than 2, such as 3 or more stacked layers.

The grapheme carbon particles may have a relatively low bulk density. For example, grapheme carbon particles used in certain embodiments of the invention are characterized as having a bulk density (tap density) of less than 0.2g/cm ³, such as no greater than 0.1g/cm ³. For the purposes of the present invention, the bulk density of the milled grapheme carbon particles was determined by placing 0.4 grams of grapheme carbon particles in a glass graduated cylinder with a readable scale. The grapheme carbon particles were precipitated within the cylinder by striking the bottom of the cylinder against a hard surface, lifting the cylinder approximately 1 inch and tapping 100 times. The volume of the particles was then measured and the bulk density, expressed in g/cm ³, was calculated by dividing 0.4 grams by the measured volume.

The compressed density and percent densification of the grapheme carbon particles may be less than the compressed density and percent densification of the graphite powder and certain types of substantially flat grapheme carbon particles. Lower compression densities and lower densification percentages are presently believed to be more conducive to better dispersion and/or rheological properties than grapheme carbon particles exhibiting higher compression densities and higher densification percentages. In certain embodiments, the grapheme carbon particles have a compressed density of 0.9 or less, such as less than 0.8, less than 0.7, such as 0.6 to 0.7. In certain embodiments, the percent densification of the grapheme carbon particles is less than 40%, such as less than 30%, such as 25% to 30%.

For the purposes of the present invention, the compressed density of grapheme carbon particles is calculated from the measured thickness of a given mass particle after compression. Specifically, the measured thickness was determined by cold pressing 0.1 gram of grapheme carbon particles in a 1.3 cm mold at 15,000 pounds force for 45 minutes with a contact pressure of 500MPa. The compressed density of the grapheme carbon particles was then calculated from the measured thickness according to the following equation:

The percent densification of the grapheme carbon particles was then determined as the ratio of the calculated compressed density of the grapheme carbon particles to the graphite density of 2.2g/cm ³ as determined above.

The measured bulk liquid conductivity of the grapheme carbon particles may be at least 100 microsiemens, such as at least 120 microsiemens, such as at least 140 microsiemens, immediately after mixing and at a later point in time, such as 10 minutes, or 20 minutes, or 30 minutes or 40 minutes. For the purposes of the present invention, the bulk liquid conductivity of grapheme carbon particles is determined as follows. First, a sample containing a 0.5% solution of grapheme carbon particles in butyl cellosolve was sonicated with a bath sonicator for 30 minutes. Immediately after sonication, the samples were placed in a standard calibrated conductivity cell (k=1). A FISHER SCIENTIFIC AB 30 conductivity meter was introduced into the sample to measure the conductivity of the sample. Conductivity was plotted over the course of about 40 minutes.

The grapheme carbon particles may be substantially free of unwanted or deleterious materials. For example, grapheme carbon particles may contain zero or only trace amounts of Polycyclic Aromatic Hydrocarbons (PAHs), such as less than 2 wt.% PAHs, less than 1 wt.% PAHs, or zero PAHs.

The starting grapheme carbon nanoparticles used in the present invention may be produced, for example, by heat treatment. According to embodiments of the present invention, thermally produced grapheme carbon particles are made from a carbonaceous precursor material that is heated to an elevated temperature in a hot zone such as a plasma. A carbon-containing precursor, such as a hydrocarbon provided in gaseous or liquid form, is heated in the hot zone to produce grapheme carbon particles in or downstream of the hot zone. For example, thermally produced grapheme carbon particles may be manufactured by the systems and methods disclosed in U.S. Pat. nos. 8,486,363, 8,486,364, and 9,221,688.

Grapheme carbon particles may be prepared by using the apparatus and methods described in U.S. patent No. 8,486,363, wherein (i) one or more hydrocarbon precursor materials capable of forming two carbon segment species (such as n-propanol, ethane, ethylene, acetylene, vinyl chloride, 1, 2-dichloroethane, allyl alcohol, propionaldehyde, and/or vinyl bromide) are introduced into a hot zone (such as a plasma), and (ii) the hydrocarbons are heated in the hot zone to a temperature of at least 1,000 ℃ to form grapheme carbon particles. Grapheme carbon particles may be produced by using the apparatus and methods described in U.S. patent No. 8,486,364, wherein (i) a methane precursor material (such as a material comprising at least 50% methane, or in some cases, at least 95% or 99% or higher purity gaseous or liquid methane) is introduced into a hot zone (such as a plasma), and (ii) the methane precursor is heated in the hot zone to form grapheme carbon particles. Such methods can produce grapheme carbon particles having at least some, and in some cases all, of the features described above.

During the production of grapheme carbon particles by the thermal production process described above, a carbon-containing precursor is provided as a feed that may be contacted with an inert carrier gas. The carbonaceous precursor material may be heated in the hot zone, for example, by a plasma system, such as a DC plasma, RF plasma, microwave plasma, or the like. In certain embodiments, the precursor material is heated to a temperature of greater than 2,000 ℃ to 20,000 ℃ or higher, such as 3,000 ℃ to 15,000 ℃. For example, the temperature of the hot zone may range from 3,500 ℃ to 12,000 ℃, such as from 4,000 ℃ to 10,000 ℃. While the hot zone may be created by a plasma system, it should be appreciated that any other suitable heating system may be used to create the hot zone, such as various types of furnaces, including electrically heated tube furnaces and the like.

The gas stream may be contacted with one or more quench streams injected into the plasma chamber through at least one quench stream injection port. The quench stream may cool the gas stream to promote the formation of grapheme carbon particles or to control their particle size or morphology. In certain embodiments of the invention, after the gaseous product stream is contacted with the quench stream, the ultrafine particles may pass through a converging means. After leaving the plasma system, grapheme carbon particles may be collected. The grapheme carbon particles may be separated from the gas stream using any suitable means, such as bag filters, cyclones, or deposited on a substrate.

Without being bound by any theory, it is presently believed that the foregoing method of making grapheme carbon nanoparticles is particularly suitable for producing grapheme carbon nanoparticles having a relatively low thickness and a relatively high aspect ratio as well as a relatively low oxygen content as described above. Furthermore, in contrast to the production of predominantly particles having a substantially two-dimensional (or planar) morphology, it is presently believed that such methods can produce a large number of grapheme carbon nanoparticles having a substantially curved, curled, wrinkled, or buckled morphology (referred to herein as a "3D" morphology). This characteristic is believed to be reflected in the compressive density characteristics described previously and is believed to be beneficial to the present invention because it is presently believed that "edge-to-edge" and "edge-to-face" contact between grapheme carbon particles within the composition can be facilitated when a substantial portion of the grapheme carbon particles have a 3D morphology. This is believed to be because particles having a 3D morphology are less likely to aggregate in the composition (due to lower van der waals forces) than particles having a two-dimensional morphology. Furthermore, it is presently believed that even in the case of "face-to-face" contact between particles having a 3D morphology, since the particles may have more than one plane of faces, the entire particle surface does not undergo a single "face-to-face" interaction with another single particle, but rather may participate in interactions with other particles in other planes, including other "face-to-face" interactions. Thus, grapheme carbon particles having a 3D morphology may provide good electrical and/or thermal pathways in the dispersion and may be used to obtain electrical and/or thermal properties. In addition, 3D morphology may provide super lubricity in certain formulations.

The dispersant resin may comprise an addition polymer. The addition polymer may be derived from and contain structural units comprising residues of one or more alpha, beta-ethylenically unsaturated monomers, such as those discussed below, and may be prepared by polymerizing a reaction mixture of such monomers. The monomer mixture may comprise one or more ethylenically unsaturated monomers containing active hydrogen groups. The reaction mixture may also contain ethylenically unsaturated monomers containing heterocyclic groups. As used herein, an ethylenically unsaturated monomer comprising a heterocyclic group refers to a monomer having at least one α, β ethylenically unsaturated group and at least one cyclic moiety having at least one atom in addition to carbon in the ring structure, such as, for example, oxygen, nitrogen or sulfur. Non-limiting examples of ethylenically unsaturated monomers containing heterocyclic groups include vinyl pyrrolidone, vinyl caprolactam, and the like. The reaction mixture may additionally comprise other ethylenically unsaturated monomers, such as alkyl esters of (meth) acrylic acid and other monomers described below.

The addition polymer may comprise a (meth) acrylic polymer comprising structural units comprising residues of one or more (meth) acrylic monomers. The (meth) acrylic polymer may be prepared by polymerizing a reaction mixture of α, β -ethylenically unsaturated monomers comprising one or more (meth) acrylic monomers and optionally other ethylenically unsaturated monomers. As used herein, the term "(meth) acrylic monomer" refers to acrylic acid, methacrylic acid, and monomers derived therefrom, including alkyl esters of acrylic acid and methacrylic acid, and the like. As used herein, the term "(meth) acrylic polymer" refers to a polymer derived from or comprising structural units comprising residues of one or more (meth) acrylic monomers. The monomer mixture may comprise one or more of an active hydrogen group-containing (meth) acrylic monomer, a heterocyclic group-containing ethylenically unsaturated monomer, and other ethylenically unsaturated monomers. The (meth) acrylic polymer may also be prepared in a reaction mixture with an epoxy functional ethylenically unsaturated monomer such as glycidyl methacrylate, and the epoxy functionality on the resulting polymer may be post-reacted with a beta-hydroxy functional acid such as citric acid, tartaric acid, and/or 3-hydroxy-2-naphthoic acid to produce hydroxyl functionality on the (meth) acrylic polymer.

The addition polymer may comprise structural units comprising alkyl (meth) acrylate residues having 8 to 22 carbon atoms in the alkyl group. Non-limiting examples of alkyl (meth) acrylates having 8 to 22 carbon atoms in the alkyl group include octyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, behenyl (meth) acrylate, stearyl (meth) acrylate, and lauryl (meth) acrylate. As a specific example, lauryl methacrylate may be used. Structural units comprising alkyl (meth) acrylate residues having 8 to 22 carbon atoms in the alkyl group may comprise at least 5wt%, such as at least 10wt%, such as at least 20 wt%, such as at least 30 wt%, such as at least 50 wt%, such as at least 70 wt%, based on the total weight of the addition polymer.

The addition polymer may comprise structural units comprising hydroxyalkyl ester residues. Non-limiting examples of hydroxyalkyl esters include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. The structural units comprising the hydroxyalkyl ester residues may comprise at least 0.5 wt%, such as at least 1 wt%, such as at least 2 wt%, and may be no more than 30 wt%, such as no more than 20 wt%, such as no more than 10 wt%, such as no more than 5 wt%, based on the total weight of the addition polymer. Structural units comprising hydroxyalkyl ester residues may comprise 0.5 to 30 wt%, such as 1 to 20 wt%, such as 2 to 20 wt%, 2 to 10 wt%, such as 2 to 5 wt%, based on the total weight of the addition polymer. The addition polymer may be derived from a reaction mixture comprising from 0.5 wt% to 30 wt%, such as from 1 wt% to 20 wt%, such as from 2 wt% to 20 wt%, from 2 wt% to 10 wt%, such as from 2 wt% to 5 wt% of a hydroxyalkyl ester, based on the total weight of polymerizable monomers used in the reaction mixture. Inclusion of structural units comprising hydroxyalkyl ester residues in the dispersant results in the dispersant comprising at least one hydroxyl group (although hydroxyl groups may be included by other means).

The addition polymer may comprise structural units comprising a vinyl heterocyclic amide residue. Non-limiting examples of vinyl heterocyclic amides include vinyl pyrrolidone, vinyl caprolactam, and the like. The structural units comprising residues of ethylenically unsaturated monomers comprising heterocyclic groups may comprise at least 0.5 wt%, such as at least 1 wt%, such as at least 10 wt%, such as at least 20 wt%, such as at least 40 wt%, such as at least 50 wt%, and may be no greater than 90 wt%, such as no greater than 85 wt%, such as no greater than 60 wt%, such as no greater than 50 wt%, such as no greater than 40 wt%, such as no greater than 30 wt%, such as no greater than 20 wt%, based on the total weight of the addition polymer. The structural units comprising residues of ethylenically unsaturated monomers comprising heterocyclic groups may comprise from 0.5 wt.% to 99 wt.%, such as from 0.5 wt.% to 50 wt.%, such as from 1 wt.% to 40 wt.%, such as from 5 wt.% to 30 wt.%, from 8 wt.% to 27 wt.%, such as from 10 wt.% to 90 wt.%, such as from 15 wt.% to 60 wt.%, such as from 15 wt.% to 50 wt.%, such as from 40 wt.% to 85 wt.%, such as from 50 wt.% to 85 wt.%, based on the total weight of the addition polymer. The addition polymer may be derived from a reaction mixture comprising an ethylenically unsaturated monomer comprising from 0.5 wt.% to 50 wt.% of heterocyclic groups, such as from 1 wt.% to 40 wt.%, such as from 5 wt.% to 30 wt.%, from 8 wt.% to 27 wt.%, such as from 10 wt.% to 90 wt.%, such as from 15 wt.% to 60 wt.%, such as from 15 wt.% to 50 wt.%, such as from 40 wt.% to 85 wt.%, such as from 50 wt.% to 85 wt.%, based on the total weight of polymerizable monomers used in the reaction mixture.

The addition polymer may contain structural units comprising residues of other alpha, beta-ethylenically unsaturated monomers. Non-limiting examples of other α, β -ethylenically unsaturated monomers include vinyl aromatic compounds such as styrene, α -methylstyrene, α -chlorostyrene, and vinyl toluene; organic nitriles such as acrylonitrile and methacrylonitrile; allyl monomers such as allyl chloride and allyl cyanide; monomeric dienes such as1, 3-butadiene and 2-methyl-1, 3-butadiene; and acetoacetoxyalkyl (meth) acrylates such As Acetoacetoxymethacrylate (AAEM), which may be self-crosslinking. The structural units comprising the residues of the other α, β -ethylenically unsaturated monomers may comprise at least 0.5 wt%, such as at least 1 wt%, such as at least 2 wt%, and may be no greater than 30 wt%, such as no greater than 20 wt%, such as no greater than 10 wt%, such as no greater than 5 wt%, based on the total weight of the addition polymer. Structural units comprising residues of other α, β -ethylenically unsaturated monomers may comprise from 0.5 wt.% to 30 wt.%, such as from 1 wt.% to 20 wt.%, such as from 2 wt.% to 20 wt.%, from 2 wt.% to 10 wt.%, such as from 2 wt.% to 5 wt.%, based on the total weight of the addition polymer. The addition polymer may be derived from a reaction mixture comprising from 0.5 wt% to 30 wt% of other α, β -ethylenically unsaturated monomers, such as from 1 wt% to 20 wt%, such as from 2 wt% to 20 wt%, from 2 wt% to 10 wt%, such as from 2 wt% to 5 wt%, based on the total weight of polymerizable monomers used in the reaction mixture.

The addition polymer may be prepared by conventional free radical initiated solution polymerization techniques in which the polymerizable monomer is dissolved in a second organic medium comprising a solvent or solvent mixture and polymerized in the presence of a free radical initiator until conversion is complete. The second organic medium used to prepare the addition polymer may be the same as the organic medium present in the dispersion composition so that the composition of the organic medium is not altered by the addition of the addition polymer solution. For example, the second organic medium may comprise the same main solvent and co-solvent in the same proportions as the organic medium of the dispersion composition. Or the second organic medium used to prepare the addition polymer may be different and distinct from the organic medium of the dispersion composition. The second organic medium used to produce the addition polymer may comprise any suitable organic solvent or solvent mixture, including those discussed above with respect to organic media, such as, for example, aromatic200, solvesso 200, and the like.

Examples of free-radical initiators are those which are soluble in the monomer mixture, such as azobisisobutyronitrile, azobis (α, γ -methylpentanenitrile), t-butyl perbenzoate, t-butyl peroxyacetate, benzoyl peroxide, di-t-butyl peroxide and t-amyl peroxy-2-ethylhexyl carbonate.

Optionally, a chain transfer agent soluble in the monomer mixture may be used, such as an alkyl mercaptan, for example t-dodecyl mercaptan; ketones such as methyl ethyl ketone, chlorinated hydrocarbons such as chloroform. Chain transfer agents provide control of molecular weight to give the product the viscosity required for various coating applications. Tertiary dodecyl mercaptan is preferred because it results in high conversion of monomer to polymerization product.

Other structures as well as random and alternating copolymer structures can be used to prepare addition polymers including, but not limited to, block copolymers, graft copolymers, brush copolymers, star copolymers, and telechelic copolymers.

Block copolymers as used herein can be generally described by the structures [ A ] -B [ B ], wherein "B" represents a block structure and "r" represents a random structure. Although many block copolymers, including one set forth in the present invention, are diblock copolymers, it is not uncommon to have additional blocks. The blocks of the block copolymer may be synthesized in any order (sequence) to achieve resin properties. However, there may be some comprehensive limitations to the choice of block order. The individual blocks of the block copolymer may be homopolymers or may be copolymers of two or more monomers. Complete conversion of the first monomer is not required prior to synthesis of the second block, so the second block may be a copolymer of residual monomer from the first block and monomer from the second block (i.e., [ A ] -B- [ A-r-B ]). This may sometimes be referred to as a "gradient" or "tapered" copolymer.

The block copolymer (e.g., diblock or triblock) may be formed via controlled radical polymerization of at least one ethylenically unsaturated monomer by the reaction of: reverse addition-fragmentation chain transfer (RAFT) mechanism, atom Transfer Radical Polymerization (ATRP), nitroxide mediated polymerization techniques and Organometallic Mediated Radical Polymerization (OMRP), most notably Cobalt Mediated Radical Polymerization (CMRP). Other methods include iodine mediated polymerization, group Transfer Polymerization (GTP), anionic polymerization, cationic polymerization. The choice of method depends on a number of parameters such as cost, compatibility with the chosen monomer, tolerance to functional groups, operating temperature, whether a catalyst (e.g. metal) is not desired in the final product, etc. It will be appreciated that the first, second and (if used) third blocks of the block copolymer can be produced in any order (sequence) and that one of the blocks can be reacted with the first and/or second components.

As used herein, the term "controlled radical polymerization" and related terms such as "controlled radical polymerization process" include, but are not limited to, ATRP, single Electron Transfer (SET) polymerization, RAFT, and nitroxide mediated polymerization.

Controlled radical polymerizations, such as RAFT and other polymerizations listed above, are generally described as "living polymerizations," i.e., chain-growth polymerizations that propagate substantially without chain transfer and substantially without chain termination. The molecular weight of the polymer produced by controlled radical polymerization may be controlled by the stoichiometry of the reactants, such as the initial concentration of the one or more monomers and the one or more initiators. Controlled radical polymerization techniques allow the polymer of one monomer to be chain extended with a second type of polymer to produce a block copolymer. In addition, controlled radical polymerization also provides polymers having characteristics including narrow molecular weight distribution, such as polydispersity index (PDI) values within a desired range; and/or well-defined polymer chain structures such as block copolymers and alternating copolymers.

The ATRP process can be generally described as comprising: polymerizing one or more free radically polymerizable monomers in the presence of an initiating system and forming a polymer. The initiation system may include an initiator having at least one radically transferable atom or group; a transition metal compound, such as a catalyst, that participates in a reversible redox cycle with the initiator; and a ligand coordinated to the transition metal compound. The ATRP process is described in further detail in U.S. patent nos. 5,763,548, 5,789,487, 5,807,937, 6,538,091, 6,887,962, 7,572,874, 7,893,173, 7,893,174 and 8,404,788.

Reversible addition-fragmentation chain transfer, or RAFT polymerization, is one of several reversible-inactivating free radical polymerizations. Which utilizes chain transfer agents in the form of thiocarbonylthio or similar compounds (such as dithioesters, thiocarbamates and xanthates; also known as RAFT agents) to mediate polymerization via a reversible chain transfer process to control the molecular weight, structure and polydispersity generated during free radical polymerization.

Nitroxide mediated free radical polymerization is a free radical polymerization process that utilizes alkoxyamine initiators to produce polymers with well controlled stereochemistry and very low polydispersity index. This is a reversible deactivated radical polymerization.

The grapheme carbon nanoparticle dispersions of the present invention can be used to produce various types of material compositions. The composition may comprise any of a variety of thermoplastic and/or thermosetting compositions known in the art. For example, the coating composition may comprise a polymer selected from the group consisting of epoxy resins, acrylic polymers, polyester polymers, polyurethane polymers, polyamide polymers, polyether polymers, bisphenol a based epoxy polymers, polysiloxane polymers, styrene, ethylene, butylene, copolymers thereof, and mixtures thereof. In general, these polymers may be any of these types of polymers prepared by any method known to those skilled in the art. Such polymers may be solvent-borne, water-soluble or water-dispersible, emulsifiable or of limited water-solubility. Furthermore, the polymer may be provided as a sol-gel system, as a core-shell polymer system, or as a powder. In certain embodiments, the polymer is a dispersion, such as an emulsion polymer or a non-aqueous dispersion, in a continuous phase comprising water and/or an organic solvent.

In addition to the resin and grapheme carbon nanoparticle components, coatings or other materials according to certain embodiments of the present invention may include additional components such as cross-linking agents, pigments, colorants, flow aids, defoamers, dispersants, solvents, UV absorbers, catalysts, and surfactants that are conventionally added to coating or ink compositions.

Thermosetting or curable coating compositions typically comprise a film-forming polymer or resin having functional groups reactive with itself or a crosslinker. The functional groups on the film-forming resin may be selected from any of a variety of reactive functional groups including, for example, carboxylic acid groups, amine groups, epoxy groups, hydroxyl groups, thiol groups, carbamate groups, amide groups, urea groups, isocyanate groups (including blocked isocyanate groups and tri-alkylcarbamoyltriazine) thiol groups, styrene groups, anhydride groups, acetoacetate acrylates, uretdiones, and combinations thereof.

The thermosetting coating composition generally comprises a crosslinking agent, which may be selected from, for example, aminoplasts, polyisocyanates including blocked isocyanates, polyepoxides, beta-hydroxyalkylamides, polyacids, anhydrides, organometallic acid functional materials, polyamines, polyamides, and mixtures of any of the foregoing. Suitable polyisocyanates include polyfunctional isocyanates. Examples of the polyfunctional polyisocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and aromatic diisocyanates such as toluene diisocyanate and 4,4' -diphenylmethane diisocyanate. The polyisocyanate may be blocked or unblocked. Examples of other suitable polyisocyanates include isocyanurate trimers, allophanates and cyclic diureas of diisocyanates. Examples of commercially available polyisocyanates include DESMODUR N3390 sold by Bayer and TOLONATE HDT90 sold by Rhodia. Suitable aminoplasts include condensates of amines and/or amides with aldehydes. For example, condensates of melamine with formaldehyde are suitable aminoplasts. Suitable aminoplasts are well known in the art. Suitable aminoplasts are disclosed, for example, in U.S. Pat. No. 6,316,119, column 5, lines 45-55, which is incorporated herein by reference. In certain embodiments, the resin may be self-crosslinking. Self-crosslinking means that the resin contains functional groups capable of reacting with itself, such as alkoxysilane groups, or that the reaction product contains co-reactive functional groups, such as hydroxyl groups and blocked isocyanate groups.

The dry film thickness of the cured coating may generally be in the range of less than 0.5 microns to 100 microns or more, for example 1 to 50 microns. As a specific example, the thickness of the cured coating may be in the range of 1 to 15 microns. However, both significantly greater coating thicknesses and significantly greater material sizes of non-coating materials are within the scope of the present invention.

As used herein, molecular weight is determined by gel permeation chromatography using polystyrene standards. Molecular weights are based on weight average unless otherwise indicated.

In certain aspects of the invention, graphene carbon nanoparticle dispersions are useful for preparing lithium ion battery cathodes and anodes. A lithium ion battery may include an anode, a cathode, a separator between the anode and the cathode, and an electrolyte in contact with the anode and the cathode. The housing is in electrical contact with the anode and the terminal is in electrical contact with the cathode.

The electrolyte of a lithium ion battery may generally comprise a lithium-containing electrolyte salt dissolved in an organic solvent. Examples of lithium-containing electrolyte salts include LiClO₄、LiAsF₆、LiPF₆、LiBF₄、LiB(C₆H₅)₄、LiB(C₂O₄)₂、CH₃SO₃Li、CF₃SO₃Li、LiCl、LiBr and the like. Examples of the organic solvent include propylene carbonate, ethylene carbonate, diethyl carbonate, dimethyl carbonate, 1, 2-dimethoxyethane, 1, 2-diethoxyethane, gamma-butyrolactone, tetrahydrofuran, 2-methyltetrahydrofuran, 1, 3-dioxolane, 4-methyl-1, 3-dioxolane, diethyl ether, sulfolane, methyl sulfolane, acetonitrile, propionitrile, anisole, acetate, butyrate, propionate and the like. Cyclic carbonates such as propylene carbonate, or chain carbonates such as dimethyl carbonate and diethyl carbonate may be used. These organic solvents may be used singly or in combination of two or more. In certain embodiments, the electrolyte may also contain additives or stabilizers such as VC (ethylene carbonate), VEC (ethylene carbonate), FEC (fluoroethylene carbonate), EA (ethylene acetate), TPP (triphenyl phosphate), phosphazene, liBOB, liBETI, liTFSI, BP (biphenyl), PS (propylene sulfite), ES (ethylene sulfite), AMC (allyl methyl carbonate), and APV (divinyl adipate).

The grapheme carbon nanoparticle dispersion can be used to prepare lithium ion battery cathode materials as disclosed in U.S. patent No. 9,761,903, incorporated herein by reference. The grapheme carbon nanoparticle dispersion can be used to prepare lithium ion battery anode materials as disclosed in U.S. patent application publication No. 2014/0272591, which is incorporated herein by reference.

The cathode of a lithium ion battery may include a lithium-containing active material, grapheme carbon nanoparticles from the present dispersion, and a binder. The cathode may include a conductive substrate such as a metal foil containing Al, a carbon-coated aluminum foil, an aluminum porous metal body, or the like. The coating of cathode material may be deposited and cured on the substrate to form a coating having a typical dry film thickness of 5 or 10 to 500 microns, such as 20 or 25 to 200 microns, such as 50 to 100 microns.

The lithium-containing active material of the cathode coating may include LiFePO ₄, carbon-coated lithium iron phosphate, lithium cobalt oxide, lithium nickel cobalt aluminate, lithium manganate, lithium nickel cobalt manganate, and the like. For example, the lithium-containing active material comprises 50 to 99.9 wt%, such as 80 to 99.5 wt%, or 87 to 99 wt%, of the cured cathode coating material. The grapheme carbon nanoparticles may generally comprise from 0.25 to 25 weight percent of the cured cathode coating material, such as from 0.5 to 10 weight percent, or from 1 or 2 to 8 weight percent.

The binder may typically comprise polyvinylidene fluoride (PVDF), acrylic, cellulosic plastics such as carboxymethyl cellulose, and the like. The binder may comprise from 0.25 to 25 wt% of the cured cathode coating material, for example from 0.5 to 10 wt%, or from 1 or 2 to 8 wt%.

The anode of a lithium ion battery may comprise a conductive substrate, such as a copper foil or other metal foil, with a graphene-containing carbon nanoparticle-containing coating deposited on one or both sides thereof. The anode material comprising grapheme carbon particles may comprise a mixture of grapheme carbon nanoparticles with lithium reactive particles such as Si and/or Sn and a binder.

The anode material may comprise 15 to 85 wt% lithium-reactive metal particles, 3 to 75 wt% grapheme carbon nanoparticles, and 3 to 60 wt% binder. For example, the lithium-reactive metal particles may comprise 25 to 70 wt%, or 30 to 50 wt%. For example, grapheme carbon nanoparticles may comprise 10 to 60 wt%, or 30 to 50 wt%.

The lithium-reactive metal particles may comprise Si, sn, or a combination thereof. The average particle size of the lithium-reactive metal particles may generally be less than 1,000 nanometers, for example, 5 to 200 nanometers, or 10 to 120 nanometers.

The binder of the anode material may comprise a polymer. For example, the polymeric binder may include poly (acrylic acid) (PAA), acrylate polymers containing greater than 5wt% acrylic acid, carboxymethyl cellulose, polymethacrylic acid, acrylate polymers containing greater than 5wt% methacrylic acid, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), acrylic latex dispersions, and the like.

In view of the foregoing, the present invention thus relates to, but is not limited to, the following:

aspect 1. A dispersion comprising a solvent; graphene carbon nanoparticles; and a polymeric dispersant resin.

Aspect 2 the dispersion of aspect 1, wherein the grapheme carbon nanoparticles have an average aspect ratio of greater than 3:1 and a raman 2d:g peak ratio of at least 1:1.

Aspect 3 the dispersion of aspects 1 or 2, wherein the polymeric dispersant resin comprises an addition polymer comprising a vinyl heterocyclic amide residue.

Aspect 4. The dispersion of aspect 3, wherein the vinyl heterocyclic amide comprises vinyl pyrrolidone.

Aspect 5 the dispersion of any one of the preceding aspects, wherein the dispersion has an instability index of less than 0.7.

Aspect 6 the dispersion of any one of the preceding aspects, wherein the grapheme carbon nanoparticles comprise greater than 5 weight percent based on the total weight of the dispersion.

Aspect 7. The dispersion of aspect 6, wherein the dispersion has an instability index of less than 0.7.

Aspect 8 the dispersion of aspect 6, wherein the instability index is less than 0.3.

Aspect 9 the dispersion of any one of the preceding aspects, wherein the dispersion has a instability index that is less than the instability index of the same dispersion containing grapheme carbon nanoparticles having a raman 2d to g peak ratio of less than 0.9:1.

Aspect 10 the dispersion of any one of the preceding aspects, wherein the polymeric dispersant comprises polyvinylpyrrolidone.

Aspect 11 the dispersion of aspect 10, wherein the polyvinylpyrrolidone has a weight average molecular weight of 1,000 to 2,000,000.

Aspect 12 the dispersion of any one of the preceding aspects, wherein the grapheme carbon nanoparticles are thermally produced at a temperature of at least 3,500 ℃.

Aspect 13 the dispersion of any one of the preceding aspects, wherein the grapheme carbon nanoparticles are milled.

Aspect 14 the dispersion of any one of the preceding aspects, wherein the grapheme carbon particles are turbostratic and have a b.e.t. specific surface area of at least 70 square meters per gram.

Aspect 15 the dispersion of any one of the preceding aspects, wherein the solvent comprises water.

Aspect 16 the dispersion of any one of the preceding aspects, wherein the solvent comprises an organic solvent.

Aspect 17 the dispersion of aspect 16, wherein the organic solvent comprises oil, N-methyl-2-pyrrolidone, benzyl alcohol, diethylene glycol monoethyl ester (DE) acetate, and/or triethyl phosphate.

Aspect 18 the dispersion of aspect 16, wherein the organic solvent comprises an oil.

Aspect 19. The dispersion of aspect 16, wherein the organic solvent comprises N-methyl-2-pyrrolidone.

Aspect 20 the dispersion of any one of the preceding aspects, wherein the weight ratio of grapheme carbon nanoparticles to the dispersant resin is from 0.5:1 to 15:1.

Aspect 21 the dispersion of aspect 1, wherein the polymeric dispersant resin comprises an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer, or a combination thereof.

Aspect 22. The dispersion of aspect 21, wherein the dispersion has an instability index of less than 0.5.

Aspect 23 the dispersion of aspects 21 or 22, wherein the grapheme carbon nanoparticles comprise greater than 3 weight percent based on the total weight of the dispersion.

Aspect 24 the dispersion of any one of aspects 21-23, wherein the instability index is less than 0.3.

Aspect 25 the dispersion of any one of aspects 21-24, wherein the polymeric dispersant addition polymer comprises an alkyl (meth) acrylate residue having 8 to 22 carbon atoms in the alkyl group, a vinyl heterocyclic amide residue, or a combination thereof.

Aspect 26 the dispersion of aspect 25, wherein the alkyl (meth) acrylate containing 8 to 22 carbon atoms in the alkyl group comprises lauryl methacrylate or stearyl acrylate.

Aspect 27 the dispersion of any one of aspects 26-26, wherein the vinyl heterocyclic amide comprises vinyl pyrrolidone.

Aspect 28 the dispersion of any one of aspects 21-27, wherein the grapheme carbon nanoparticles are thermally produced at a temperature of at least 3,500 ℃.

Aspect 29 the dispersion of any one of aspects 21-28, wherein the grapheme carbon nanoparticles have an average aspect ratio of greater than 3:1 and a raman 2d:g peak ratio of at least 1:1.

Aspect 30 the dispersion of any one of aspects 21-29, wherein the grapheme carbon particles are turbostratic and have a b.e.t. specific surface area of at least 70 square meters per gram.

Aspect 31 the dispersion of any one of aspects 21-30, wherein the grapheme carbon nanoparticles are milled.

Aspect 32 the dispersion of any one of aspects 21-31, wherein the organic solvent comprises oil, N-methyl-2-pyrrolidone, benzyl alcohol, diethylene glycol monoethyl ester (DE) acetate, and/or triethyl phosphate.

Aspect 33 the dispersion of any one of aspects 21-31, wherein the organic solvent comprises an oil.

Aspect 34 the dispersion of any one of aspects 21-31, wherein the organic solvent comprises N-methyl-2-pyrrolidone.

The dispersion of any one of aspects 21-34, wherein the weight ratio of grapheme carbon nanoparticles to the dispersant resin is from 0.5:1 to 15:1.

Aspect 36. A method of dispersing grapheme carbon nanoparticles in a solvent comprising mixing a dispersant resin into the solvent, wherein the dispersant resin comprises an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer, or a combination thereof; and mixing the grapheme carbon nanoparticles into the solvent and dispersant resin mixture.

Aspect 37 the method of aspect 36, wherein the addition polymer comprises a vinyl heterocyclic amide residue.

Aspect 38 the method of aspect 36 or 37, further comprising milling the grapheme carbon nanoparticles prior to mixing the grapheme carbon nanoparticles into the solvent and dispersant resin mixture.

Aspect 39 the method of any one of aspects 36-38, wherein the grapheme carbon nanoparticles have an average aspect ratio of greater than 3:1 and a raman 2d:g peak ratio of at least 1:1.

Aspect 40 a dispersion prepared by the method of any one of aspects 36-39.

Aspect 41. The dispersion of aspect 40, wherein the dispersion comprises the dispersion of any one of aspects 1-35.

Aspect 42. A lubricant comprising the dispersion according to any one of aspects 1-36.

Aspect 43 the lubricant of aspect 42, wherein the lubricant comprises a base oil, a dispersant resin, and grapheme carbon nanoparticles dispersed in the base oil; the dispersant resin comprises an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer, or a combination thereof.

Aspect 44. A lithium ion battery electrode slurry comprising lithium-containing active materials or lithium-reactive particles; and the dispersion of any one of aspects 1-35.

Aspect 45. A lithium ion battery electrode made from the lithium ion battery electrode slurry of aspect 44.

The following examples are intended to illustrate various aspects of the invention and are not intended to limit the scope of the invention.

Example 1

2 Grams of grapheme carbon nanoparticle (GNP) powder commercially available from Raymor produced according to the teachings of U.S. patent No. 8,486,364 was added to a 100mL plastic cup (flacketek company) having 6 zirconia beads (5 mm, very high density zirconia, 95%ZrO2,5%Y2O3,Glen Mills). The samples were mixed on a FlackTek flash mixer (DAC 600.1 FVZ) at 2350rpm for 8 minutes at 2 minute intervals. The beads were then removed from the vessel. For larger amounts, 25 grams of grapheme carbon nanoparticles were added to a 500mL plastic cup with 20 beads and mixed on a flash mixer at 2350rpm for 8 minutes at 2 minute intervals. Powder samples were then collected for analytical characterization and dispersion preparation. Deionized water may optionally be added to the grapheme carbon nanoparticles in the vessel, for example, deionized water mist may be sprayed onto the grapheme carbon nanoparticle powder in the plastic cup with a water level of 0% to 99.9%. The water-wet GNP sample can then be mixed on a flash mixer with grinding beads under the same conditions as described above.

After preparation of GNP samples by mixing with a flash mixer as described in example 1, the samples were formulated as dispersions in various aqueous and organic solvents. The milled grapheme carbon nanoparticle dispersions can be prepared using a variety of milling techniques including flash mixers, cowles blades, and Eiger mills.

Example 2

In the flash mixer dispersion, 0.34% dispersant resin (50% solids) listed in table 1 was first added to the base oil solvent in the plastic cup. The sample was mixed with 6 zirconia beads on a flash mixer for 4 minutes or longer as needed until the resin was completely dissolved. Thereafter, 0.50% of the premilled Dan Moxi powder prepared in example 1 was added to the cup of the resin-solvent mixture and mixed on a flash mixer at 2350rpm for an additional 8 minutes. This process was repeated except that the grapheme carbon nanopowder of example 1 was replaced with commercially available exfoliated graphene sold under the name M25 by XG Sciences. The weight percentages of the components in the standard base oil dispersion formulation are listed in table 1. The instability index of each dispersion was measured at 1500rpm, 313RCA (relative centrifugal acceleration), 25℃for 5 minutes using LUMiSizer, and was 0.201. Fig. 1 is a graph of instability index versus time for an oil dispersion of table 1 containing milled plasmonic carbon particles and milled exfoliated graphenic carbon particles with a graphene loading of 0.5%, where the ratio of graphene to resin is 10. Figure 1 shows that the milled plasma graphene dispersion shows significantly lower instability index and better stability than the milled commercial exfoliated graphene dispersion under the same formulation.

TABLE 1 composition of GNP Dispersion in oil (wt.%)

Component (A)
			GNP	0.50	0
M25 graphene	0	0.50
			Dispersant resin	0.17	0.17
Oil solvent	99.33	99.33

* Dispersant resin: lauryl methacrylate copolymers of vinylpyrrolidone

* Oil solvent: various types of oil solvents include, but are not limited to, stick chain oil, cutting oil, gear oil, hydraulic oil, air compressor oil, pneumatic tool oil, and the like.

Although the solid state pre-milling process can effectively improve the dispersion quality of the thermally produced turbostratic grapheme carbon nanoparticles, no significant improvement in dispersion quality was observed when the same milling process was applied to the commercially available exfoliated graphene M25.

Example 3

In the rapid mixer dispersion, 7.7% polyvinylpyrrolidone (PVP) was first added to deionized water in a plastic cup. The sample was mixed with 6 zirconia beads on a flash mixer for 4 minutes or longer as needed until the resin was completely dissolved. Thereafter, 23% of the pre-milled GNP powder prepared in example 1 was added to the cup along with PVP dispersant and solvent mixture and again mixed on a flash mixer at 2350rpm for an additional 8 minutes. The weight percentages of the components in the standard aqueous dispersion formulation are listed in table 2.

Table 2 aqueous graphene dispersions

Component (A)	Weight percent
		Deionized water	69.3％
PVP*	7.7％
		GNP	23％

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw= 10,000,Sigma Aldrich

Example 4

In the Cowles blade dispersion, 7.7% polyvinylpyrrolidone (PVP) was first added to deionized water while mixing with a Cowles blade. Once the resin was completely dissolved, 23% of the pre-ground GNP powder prepared from the GNP of example 1 was gradually added while vigorously stirring with a Cowles blade, starting at 500RPM and steadily increasing to 2000RPM as required. The mixture was then mixed on Cowles blades for 30 minutes or longer if desired. The weight percentages of the components in the standard aqueous dispersion formulation are listed in tables 3 and 4. The dispersions of Table 3 prepared using this process had an instability index of 0.335 measured at 4000rpm, 2201RCA, 25℃for 20 minutes using LUMiSizer. The instability index of the dispersions in table 4 prepared using this process was measured to be 0.582.

Table 3 aqueous graphene dispersions

Component (A)	Weight percent
		Deionized water	69.3％
PVP*	7.7％
		GNP	23％

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw= 10,000,Sigma Aldrich

Example 5

In the Eiger mill dispersion, the Cowles blade was first used for pre-dispersion. The resin is added to water or solvent while mixing with high lift or Cowles blades. Once the resin was completely dissolved, the GNP was gradually added while vigorously stirring with a Cowles blade, starting at 500RPM and steadily increasing to 2000RPM as needed. The pre-dispersion formulation was then milled using an Eiger mill with 1-1.2mm Zirconox milling media to a residence time of 20 minutes to further reduce particle size. The weight percentages of the components in the standard aqueous dispersion formulation are listed in tables 3 and 4. The dispersions in Table 3 have an instability index of 0.080 measured at 4000rpm, 2201RCA (relative centrifugal acceleration), 25℃for 20 minutes using LUMiSizer. The dispersions in Table 4 have an instability index of 0.511 measured at 4000rpm, 2201RCA, 25℃for 20 minutes using LUMiSizer. Fig. 2 is a graph of instability index versus time for an aqueous dispersion containing milled plasmonic carbon particles (20% graphene loading) and milled exfoliated graphenic carbon particles (8% graphene loading), where the ratio of graphene to resin is 3. The figure shows that 20% of the milled plasmonic graphene dispersion exhibited significantly lower instability index and better stability than 8% of the milled exfoliated graphene dispersion.

Table 4 aqueous graphene dispersions

Component (A)	Weight percent
		Deionized water	89.3％
PVP*	2.7％
		GNP	8％

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw= 10,000,Sigma Aldrich

Example 6

Compositions were prepared using the components listed in table 5.

TABLE 5

⁴ PVP, polyvinylpyrrolidone, CAS#9003-39-8 from SIGMA ALDRICH

⁵ Grapheme carbon particles are thermally produced according to the method disclosed in U.S. patent No. 8,486,364, having a BET specific surface area of at least 300m ²/g, an average number of layers of 7, a flake size of 150-200nm, commercially available as PureWave Graphene (GNP) from Raymor NanoIntgris.

The components in table 5 constitute an aqueous (wb) grapheme carbon nanoparticle pre-dispersion formulation. First, PVP is added to water while mixing with high lift or Cowles blades. Once the PVP was completely dissolved in water, the GNP was gradually added while vigorously stirring with a Cowles blade, starting at 500RPM and steadily increasing to 2000RPM as needed. The pre-dispersion formulation in Table 5 was milled to a residence time of 20 minutes using an Eiger mill with 1-1.2mm Zirconox milling media to reduce particle size to less than 1 μm.

As shown in table 6, the particle size, instability and rheology of the pre-dispersions and grind dispersions of table 5 were analyzed.

TABLE 6

⁶ Particle size-measured by a Mastersizer 2000, an analytical technique for measuring particle size distribution, from Melvern Instruments

⁷ Instability index-measured by LUMiSizer, LUMiSizer is an analytical technique for accelerating instability from LUM GmbH, measured at 4000rpm for 60 seconds

⁸ High shear and Low shear viscosity-measurement of example 7 using an Anton Paar rheometer from Anton Paar

In the Cowles blade dispersion, 40% LMA-VP resin (50% solids) was first added to the base oil solvent while mixing with the Cowles blade. Once the resin was completely dissolved, 20% of the pre-grind Dan Moxi powder prepared in example 1 was gradually added while vigorously stirring with a Cowles blade, starting at 500RPM and steadily increasing to 2000RPM as needed. The mixture was then mixed on Cowles blades for 30 minutes or longer if desired. The weight percentages of the components in the standard dispersion formulation are listed in table 7.

TABLE 7 composition of GNP Dispersion in oil

Component (A)	Weight percent
		GNP	20
Dispersant resin	20
		Resin solvent	20
Oil solvent	40

* Dispersant resin: lauryl methacrylate copolymers of vinylpyrrolidone

Example 8

In the rapid mixer dispersion, 0.5% polyvinylpyrrolidone (PVP) was first added to N-methyl-2-pyrrolidone (NMP) in a plastic cup. The sample was mixed with 6 zirconia beads on a flash mixer for 4 minutes or longer as needed until the resin was completely dissolved. Thereafter, 5% of the pre-milled graphene powder prepared in example 1 was added to the cup of the resin-solvent mixture and mixed again on a flash mixer at 2350rpm for an additional 8 minutes. The weight percentages of the components in the standard aqueous dispersion formulation are listed in table 8.

TABLE 8 composition of GNP Dispersion in N-methyl-2-pyrrolidone (NMP)

Component (A)	Weight percent
		GNP	5％
PVP*	0.5％
		NMP**	94.5％

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw= 10,000,Sigma Aldrich

* NMP, N-methyl-2-pyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

Example 9

Compositions were prepared using the components listed in table 9.

TABLE 9

Weight percent	C	D	E
				95％	⁹NMP	NMP	NMP
0.5％	PVP	¹⁰ SAR resin	¹¹PSII
				4.5％	TGC	TGC	TGC

⁹ NMP-N-methyl-2-pyrrolidone, CAS#872-50-4, from SIGMA ALDRICH

¹⁰ SAR resin-acrylic resin from PPG

¹¹ PSII-acrylic resin from PPG

The components in samples C, D and E from table 9 constitute the solvent-based grapheme carbon nanoparticle dispersion formulation. For sample C, PVP was added to NMP while mixing with Cowles blades. Once PVP was completely dissolved in NMP, TGC was gradually added while vigorously stirring with Cowles blades, starting at 500RPM and steadily increasing to 2000RPM as needed. The pre-dispersed sample C formulation was milled to a residence time of 20 minutes using an Eiger mill with 1-1.2mm Zirconox milling media.

For sample D, SAR resin was added to NMP and mixed on a FlackTek flash mixer at 2350rpm for 5 minutes. TGC was then added to the mixture and mixed on a flash mixer at 2350rpm for an additional 5 minutes. The mixing step is repeated as necessary.

For sample E, PSII resin was added to NMP and mixed on a FlackTek flash mixer at 2350rpm for 5 minutes. TGC was then added to the mixture and mixed on a flash mixer at 2350rpm for an additional 5 minutes. The mixing step is repeated as necessary.

For a better understanding of the dispersed material, an in situ optical microscope was used. In this case, graphene (0.5%) of the same concentration before and after grinding was drop cast onto a glass slide using the same dispersant (PVP 10:1P/B) and solvent (NMP) dispersion similar to example 8 above. These were observed in situ during solvent evaporation. Two qualitative observations can be made. First, as shown in fig. 4 and 5, there are more micron-sized aggregates in the produced graphene, compared to the ball milling shown in fig. 6 and 7. As the solvent evaporates, the size of the aggregates shown in fig. 4 and 5 increases. This can also be easily seen with the naked eye when the same solution is drop cast onto a silicon wafer, as shown in fig. 3.

Table 10 average particle area based on fig. 5 and 7

Drawing of the figure	Sample of	Average particle area
			5	Ball milling GNP	0.6μm²
7	Unground GNP	2.0μm²

A variety of analytical characterization techniques can be employed to monitor material quality and determine whether the desired thermal and electrical properties of graphene are retained after processing. In addition, tests can be performed to detect physical changes caused by solid state milling in order to understand the structure-performance relationship that results in improved dispersion quality and stability.

Raman, XPS and TEM can be used to monitor material quality. These can be used to test the graphite quality, purity and structure of the material. In the case of solid state milling, raman and XPS showed an increase in defect density (fig. 9) and oxygen incorporation (fig. 8) as a function of milling time. Furthermore, high magnification TEM showed that the morphology of the individual grapheme carbon nanoparticles was the same before milling (fig. 10) and after milling (fig. 11).

The dispersion properties of the solution similar to example 7 were analyzed using an Anton-Paar rheometer with parallel plate geometry (1 mm gap and 50mm diameter) with systematic variation in GNP loading. Two types of GNPs, with and without solid state milling processes, are the main distinction between the two families. NMP was used as the solvent and PVP (Mw-10000) was used as the polymer binder, and the composition was kept at 10% by weight of the weight of GNP in solution. The samples were stabilized at 25 ℃ for 5 minutes before measurement. Dynamic frequency sweep measurements were made at a constant strain of 0.1% in the Linear Viscoelastic Region (LVR) to study the dispersed structure as a function of GNP concentration to accurately determine GNP concentration at the transition from fluid to strong gel behavior.

Fig. 12 and 13 show the frequency-dependent complex moduli (G' and G ") and complex viscosity trends at the original GNP concentration (fig. 14). When the result is i) that the G' and G "values are independent of frequency ii) that the viscosity drops in a gradient of- (-1) over all applied frequency bipartite graphs, classical strong gel behavior can be determined by dynamic frequency sweep measurements. For a solution with a minimum concentration of 0.5%, the solution shows a viscoelastic response that is already close to the strong gel behavior, and all solutions above 1% show strong gel behavior.

For the series with solid state milled GNPs (fig. 15 and 16), the GNP concentration of the strong gel behavior was significantly increased by nearly 15% compared to the solution with the original GNPs (< 1%). G 'and G "were found to increase with increasing concentration, frequency-independent complex modulus (G' and G") values and viscosity (fig. 17), following the power law of (-1) in the bipartite graph, samples of ball milled GNP were observed at near 15% loading.

A significant transition in fluid-to-strong gel transition from about 1% to about 15% GNP loading was achieved by the solid phase milling process. Conventional exfoliated graphene is known to have poor dispersibility even with polymeric binders in organic and aqueous solutions, and strong gel behaviour has been reported for similar systems, with graphene loadings of mostly less than 1%. By introducing structural defects (such as oxygen of graphene oxide) the dispersibility may be slightly improved, but to date the highest graphene loading of the strong gel state is still well below 5%.

Fig. 18 is a flow curve of an aqueous graphene dispersion. The 8% raw graphene dispersion was compared to the 20% solid milled graphene dispersion. The figure shows that the solid state milling process can significantly increase the solids content of the dispersion from 8% to 20% while maintaining a comparable viscosity.

Fig. 19 shows the viscosities of 8% pristine grapheme carbon nanoparticle dispersions and 20% solid state ground grapheme carbon nanoparticle dispersions at a shear rate of 10 Hz. The figure shows that the solid state milling process can significantly increase the solids content of the dispersion from 8% to 20% while maintaining a comparable viscosity.

Figure 20 shows a graph of NMP dispersion comparing 5% pristine grapheme carbon nanoparticle dispersion to 10%, 15% solid state milled dispersion. The figure shows that 10% and 15% of the solid milled dispersions exhibit lower viscosities than the 5% standard dispersion.

Fig. 21 shows the viscosities of 5% of the pristine grapheme carbon nanoparticle dispersion and 10%, 15% of the solid state milled grapheme carbon nanoparticle dispersion at a shear rate of 10 Hz. The figure shows that 10% and 15% of the solid milled dispersions exhibit lower viscosities than the 5% standard dispersion.

It is apparent that the dispersion quality of the solid-state ground GNPs is improved by an order of magnitude compared to the original unground GNPs.

The ground grapheme carbon nanoparticles are dispersed in a hydrocarbon oil. The results show that the solid grinding can not only improve the solid content of the grapheme carbon nano particles, but also can obviously improve the quality and stability of the grapheme carbon nano particle dispersion.

As shown in the instability index plots in fig. 22, 23, and 24, the solid state milling process reduces the instability index compared to the original unground grapheme carbon nanoparticle dispersion, making such dispersions more stable at room temperature and high temperature. The instability index of each dispersion was measured using LUMiSizer at 1500rpm, 313RCA (relative centrifugal acceleration) and 25 ℃. Although fig. 22 and 23 only show a time of up to 10 minutes, the instability curve is stable at 10 minutes, so that the instability index at 20 minutes will be substantially the same as that shown at 10 minutes. The combination of grinding and resin addition provides a synergistic effect for the stabilization of grapheme carbon nanoparticle dispersions.

Solid state milling of grapheme carbon can significantly increase the solids content and stability of grapheme carbon nanoparticles in dispersion, allowing for more efficient integration of the particles into various solvent and water systems. Raman and XPS may show an increase in defect density and oxygen incorporation with increasing milling time, and rheological studies indicate that the fluid-strong gel transition increases from 1% of the dispersion made from pristine grapheme carbon nanoparticles to 15% of the dispersion made from solid milled grapheme carbon nanoparticles. The dispersion made with solid state milled grapheme carbon nanoparticles can achieve comparable cell performance (2.5 times higher solids content) in silicon anodes and better conductivity in LiFePO ₄ cathodes.

The alkyl functionalized VP resin was evaluated as a dispersant in NMP formulations suitable for lithium ion battery electrode fabrication. In a typical dispersion formulation, the dispersant resin (0.5 wt.% of dispersion solids) was dissolved in NMP in a two-way asymmetric centrifuge (DAC) cup. GNP powder (5.0 wt% of dispersion solids) was added to NMP solution and the cup was mixed for 8 minutes using a flash mixer DAC and six 5mm ceramic mixing beads. Then by usingThe dispersion analyzer measures the instability index value to evaluate the room temperature stability of each dispersion. It should be noted that lower instability index values correspond to increased dispersion stability.

Copolymer resins having an LMA content of 10 to 90% by weight were prepared using tert-amyl peroxy (2-ethylhexyl) carbonate (Trigonox 131) as radical initiator and targeting an initial [ M ]0: [ I ]0 ratio of 85:1. GNP dispersions were then prepared using the DAC mixing procedure described above and the instability index value of each resulting dispersion was measured. SAR dispersants were prepared by free radical polymerization of methyl methacrylate, 2-hydroxyethyl acrylate, methacrylic acid, 2-ethylhexyl acrylate and VP using NMP as a suitable polymerization solvent. SAR25 and SAR50 were prepared at VP incorporation levels of 25 wt.% and 50 wt.%, respectively. As shown in fig. 25, all LMA-VP copolymers provided dispersions with lower room temperature instability index values compared to commercial PVP controls (Mw-10,000 g/mol) and SAR dispersants with 25 wt% or 50 wt% VP. An increase in LMA content from 10 wt% to 70 wt% results in a decrease in the dispersion instability index, which reaches a minimum when the dispersant contains 70 wt% or 75 wt% LMA. These results indicate that LMA-VP copolymers containing 70-75 wt.% LMA are optimal for dispersing and stabilizing GNP in NMP.

As more fully described in the examples below, grapheme carbon nanoparticles were dispersed in an N-methyl-2-pyrrolidone (NMP) solution containing a polymer resin comprising N-vinylpyrrolidone, N-vinylpyrrolidone copolymerized with lauryl methacrylate (P (LMA-co-VP)) in various ratios of N-vinylpyrrolidone to lauryl methacrylate of 100:0 to 3:1, 1:1 and 1:3, the viscosity of the grapheme carbon nanoparticle dispersion decreased significantly as the lauryl methacrylate content increased, and the total solids of the dispersion remained constant at 6 wt.%. Furthermore, it is generally observed that the particle size of the grapheme carbon nanoparticles in the dispersion increases with increasing lauryl methacrylate content relative to the total solids content of the grapheme carbon nanoparticle dispersion. The results show that the increased particle size due to lauryl methacrylate content varies with decreasing viscosity of the grapheme carbon nanoparticle dispersion. The distribution of lauryl methacrylate and N-vinyl pyrrolidone in the polymer resin may also be a factor in the overall particle size and viscosity of the dispersion.

Use of a grapheme carbon nanoparticle dispersion in NMP containing varying amounts of polymer resin dispersants of lauryl methacrylate and N-vinyl pyrrolidone as a conductive additive for lithium ion battery cathodes, with LiNi _0.5Mn_0.3Co_0.2O₂ as the active material for Li-ion based energy storage, polyvinylidene fluoride as the binder, shows little effect of the grapheme carbon dispersant resin on rate performance and cycle life in coin cell form when included in a lithium ion battery electrode slurry composition. These results ensure that a grapheme carbon nanoparticle dispersion with a lower viscosity using a proportion of lauryl methacrylate and P (LMA-co-VP) of N-vinylpyrrolidone can be used in an electrochemically active Li-ion cathode membrane without significant observable degradation in cycle life or rate performance of the cell in the form of a coin cell.

The increase in lauryl methacrylate in the dispersant resin allows an increase in the total solids content in the grapheme carbon nanoparticle dispersion while achieving a desired viscosity comparable to that of using only poly (vinyl pyrrolidone) (abbreviated PVP) as the dispersant.

Example 10

Compositions were prepared under a N ₂ blanket using the ingredients listed in table 11 to protect against moisture. In the rapid mixer dispersion, PVP dispersant resin was first added to NMP along with 10 zirconia beads and mixed at 2000rpm for 2 minutes until completely dissolved/dispersed. Then, grapheme carbon nanoparticles (GNPs) were added and mixed at 2000rpm for a total of 8 minutes or until completely dispersed. The weight percentages of the components in the standard dispersion formulation are listed in table 11.

TABLE 11 GNP distribution in NMP with PVP

Component (A)	Dispersion A (wt.%)	Dispersion B (wt%)	Dispersion C (wt.%)
				NMP*	94.0	94.0	94.0
GNP	5.4	5.0	4.5
				PVP**	0.6	1.0	1.5

* NMP, N-methyl-2-pyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw=10,000 g/mol SIGMA ALDRICH

Example 11

Compositions were prepared under a N ₂ blanket using the ingredients listed in table 12 to protect against moisture. In the rapid mixer dispersion, P (LMA-co-VP) was first added to NMP along with 10 zirconia beads and mixed at 2000rpm for 2 minutes until complete dissolution/dispersion. GNP was then added and mixed at 2000rpm for a total of 8 minutes or until completely dispersed. The weight percentages of the components in the standard dispersion formulation are listed in table 12.

TABLE 12 GNP distribution in NMP with P (LMA-co-VP)

Component (A)	Dispersion A (wt.%)	Dispersion B (wt%)	Dispersion C (wt.%)
				NMP*	94.0	94.0	94.0
GNP	5.4	5.0	4.5
				Resin 1 ×	0.6	1.0	1.5

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* Copolymers of resin 1-lauryl methacrylate and N-vinylpyrrolidone, P (LMA-co-VP) dispersed in NMP in a ratio of 1:3, mw= -16,000 g/mol, respectively

Example 12

Compositions were prepared under a N ₂ blanket using the ingredients listed in table 10 to protect against moisture. In the rapid mixer dispersion, P (LMA-co-VP) was first added to NMP along with 10 zirconia beads and mixed at 2000rpm for 2 minutes until complete dissolution/dispersion. GNP was then added and mixed at 2000rpm for a total of 8 minutes or until completely dispersed. The weight percentages of the components in the standard dispersion formulation are listed in table 13.

TABLE 13 GNP distribution in NMP with P (LMA-co-VP)

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* Copolymers of resin lauryl 2-methacrylate and N-vinylpyrrolidone, P (LMA-co-VP) are dispersed in NMP in a ratio of 1:1, mw= -31,000 g/mol, respectively

Example 13

Compositions were prepared under a N ₂ blanket using the ingredients listed in table 14 to protect against moisture. In the rapid mixer dispersion, P (LMA-co-VP) was first added to NMP along with 10 zirconia beads and mixed at 2000rpm for 2 minutes until complete dissolution/dispersion. GNP was then added and mixed at 2000rpm for a total of 8 minutes or until completely dispersed. The weight percentages of the components in the standard dispersion formulation are listed in table 14.

TABLE 14 GNP distribution in NMP with P (LMA-co-VP)

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* Copolymers of resin 3-lauryl methacrylate and N-vinylpyrrolidone, P (LMA-co-VP) are dispersed in NMP in a ratio of 3:1, mw= -35,000 g/mol, respectively

Example 14

Compositions were prepared under a N ₂ blanket using the ingredients listed in table 15 to protect against moisture. In the rapid mixer dispersion, P (LMA-co-VP) was first added to NMP along with 10 zirconia beads and mixed at 2000rpm for 2 minutes until complete dissolution/dispersion. GNP was then added and mixed at 2000rpm for a total of 8 minutes or a4 x2 minute incremental mixing step was used until completely dispersed. The weight percentages of the components in the standard dispersion formulation are listed in table 15.

TABLE 15 GNP distribution in NMP with P (LMA-co-VP)

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* Copolymers of resin 4-lauryl methacrylate and N-vinylpyrrolidone, P (LMA-co-VP) being dispersed in N-amyl propionate, mw= -43,000 g/mol, respectively, in a ratio of 3:1

Example 15

To understand how changes in lauryl methacrylate content will affect the viscosity of low resin content grapheme carbon nanoparticle dispersions, rheological measurements were collected using Anton Paar MCR 302 and CP50-1/TG measuring cone. Viscosity measurements at a shear rate of 10Hz were used to compare the dispersion rheology. In each of examples 10, 11, 12 and 13, the dispersion tested was described as dispersion a, which contained a graphene to resin ratio of 9. Fig. 26 shows that at this particular resin content level, the resin has little effect on the rheological properties of the grapheme carbon nanoparticle dispersion.

Example 16

To understand how changes in the lauryl methacrylate content will affect the viscosity of a medium resin content grapheme carbon nanoparticle dispersion, rheological measurements were collected from slurries described as dispersion B in examples 10, 11, 12 and 13 at a shear rate of 10Hz, with dispersion B containing grapheme carbon nanoparticles to resin ratio of 5. Fig. 27 shows that the viscosity of the grapheme carbon nanoparticle dispersion decreased significantly as the lauryl methacrylate component increased from 0% to 75% of the polymer resin at this particular resin content level. Thus, when using a graphene to resin ratio >5, the increase in solids content may be less than about 30%.

Example 17

To understand how changes in the lauryl methacrylate content will affect the viscosity of the high resin content grapheme carbon nanoparticle dispersion, rheological measurements were collected from a slurry described as dispersion C containing a ratio of grapheme carbon nanoparticles to resin of 3 at a shear rate of 10 Hz. Fig. 28 shows that the viscosity of the grapheme carbon nanoparticle dispersion decreases significantly as the lauryl methacrylate component increases from 0% to 75% of the polymer resin at this particular resin content level. Thus, when a graphene to resin ratio <5 is used, the increase in solids content may be higher than about 30%.

Example 18

To determine the increased solids content obtainable with resins containing high levels of lauryl methacrylate, grapheme carbon dispersions were formulated at different total solids contents, but the ratio of grapheme carbon nanoparticles to resin was constant at 5. The composition of the grapheme carbon nanoparticle dispersion is shown in table 16. Fig. 29 and 30 show that when resin 3 is used instead of PVP in an NMP-based grapheme carbon nanoparticle dispersion, an increase of up to and including about 30% of the total solids can be achieved while maintaining a similar viscosity at the same shear rate as when using a graphene to resin ratio of 5.

TABLE 16 GNP Dispersion in NMP with PVP or resin 3

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH

* PVP, polyvinylpyrrolidone, CAS #9003-39-8, mw=10,000 g/mol SIGMA ALDRICH

* Copolymer of resin 3-lauryl methacrylate and N-vinylpyrrolidone, P (LMA-co-VP) is dispersed in NMP in a ratio of 3:1, mw= -35,000 g/mol, respectively

Example 19

To test the electrochemical stability of the dispersants when used in Li-ion cathode films, the grapheme carbon nanoparticle dispersions listed above were used in Li-ion cathode slurry formulations under an N ₂ coating consisting of the components listed in table 17. In the rapid mixer dispersion, the grapheme carbon nanoparticle dispersion was added to 1/2 of the desired LiNi _0.5Mn_0.3Co_0.2O₂ active material and mixed at 2000rpm for 30 seconds. Then the required additional 1/2 of the LiNi _0.5Mn_0.3Co_0.2O₂ active material was added and mixed for a total of 60 seconds at 2000rpm using a 2 x 30 second incremental mixing step. Before adding poly (vinylidene fluoride) (PVDF) to the Li-ion cathode slurry separately, PVDF was dissolved in NMP to prepare an 8 wt% solution. The resulting PVDF solution was then added to a Li-ion cathode slurry containing LiNi _0.5Mn_0.3Co_0.2O₂ and grapheme carbon nanoparticle dispersion and mixed at 2000rpm for 30 seconds. The remaining amount of NMP is then added to the slurry and mixed at 2000rpm in 30 second increments until thoroughly mixed, typically for a total time ranging from as low as 2 minutes up to 6 minutes. The film was then cast onto an aluminum foil substrate using a doctor blade method at a speed of 10mm per second, then cured at 55 ℃ for 2 minutes, then a second curing step at 120 ℃ for 2 minutes. The film is then calendered to a desired porosity of about 25% to 35%. Fig. 31-38 show scanning electron microscope images of the final Li-ion cathode film as a cross section of the film. These images show a relatively uniform distribution of grapheme carbon nanoparticles and binder in the larger secondary particle network of LiNi _0.5Mn_0.3Co_0.2O₂ particles.

TABLE 17 Li-ion cathode slurry components

Component (A)	Weight percent (%)
		LiNi_0.5Mn_0.3Co_0.2O₂	45
GNP dispersion	29
		PVDF**	1
NMP***	25

* GNP dispersions described in example 8 dispersion a and dispersion B, example 9 dispersion a and dispersion B, example 10 dispersion a and dispersion B, and example 11 dispersion a and dispersion B.

* PVDF-poly (vinylidene fluoride), solvay5130，Mw＝1,000,000-1,100,000g/mol

* NMP, N-vinylpyrrolidone, CAS#872-50-4, anhydrous, 99.5%, SIGMA ALDRICH%

Example 20

To test the electrochemical stability of the dispersants when used in Li-ion cathode films, the coin cell cells of the films described in example 19 were assembled in a VAC Atmospheres Nexus II glove box under argon, with an oxygen content <2ppm and an H ₂ O content <0.5ppm. Prior to button cell fabrication, the film was punched into 1cm ² segments for button cell fabrication and dried in vacuo at 110 ℃ for 10 hours, then placed directly into a glove box without exposure to the external atmosphere. 2032 coin cells were used for manufacturing, lithium metal was used as counter and reference electrode, and Celgard 2320 polypropylene/polyethylene/polypropylene (PP/PE/PP) was used as separator. 75 μl of 1M LiPF ₆ solution was dissolved in 3:7 ethylene carbonate/ethylmethyl carbonate and 2 wt% ethylene carbonate additive for use as electrolyte. Button cells were charged and discharged between 3.0V and 4.3V for Li at the various rates described in table 18 using a Bio-Logic BCS-805 or BCS-810 cell circulator for a total of 50 cycles in top-down order.

TABLE 18 charge and discharge rates for Li-ion coin cells

Charge/discharge C rate	Number of cycles
		0.1C	3
0.2C	3
		0.4C	3
0.8C	3
		1.6C	3
1.0C	35

As shown in fig. 39 and 40, when the lauryl methacrylate content was increased from 0% to 75% of the grapheme carbon nanoparticle dispersant and the ratio of grapheme carbon nanoparticles to resin was 9 or 5, it appeared that there was little effect on the capacity retention rate and cycle life. These results ensure that the grapheme carbon nanoparticle dispersant resulting in a reduction in the viscosity of the grapheme carbon nanoparticle dispersion can be used in Li-ion cathode electrodes with minimal impact on cell performance in the form of coin cells, with the greatest impact on rate capability at 1.6C compared to the example 10 dispersions a and B (dispersions having the highest lauryl methacrylate content) from example 11 dispersions a and B (no lauryl methacrylate in grapheme carbon nanoparticle dispersion resin).

Example 21

A dispersant resin having a random copolymer structure comprising lauryl acrylate and N-vinyl pyrrolidone monomers is prepared using free radical polymerization chemistry. In a typical preparation, solvesso 200 (23.15 g) was charged to a reactor and heated to 110℃under a constant nitrogen atmosphere. A mixture of Solvesso 200 (3.56 g) and the free radical initiator t-amyl peroxy-2-ethylhexyl carbonate (0.46 g) was then added dropwise to the reactor from the initiator feed tank over 185 minutes. Five minutes after the start of the addition of the free radical initiator solution, a mixture of lauryl acrylate (26.25 g) and N-vinyl pyrrolidone (8.75 g) was added to the reactor from the monomer feed tank over 180 minutes. After the free radical initiator and monomer feeds were completed, the monomer feed tank was flushed with Solvesso 200 (3.56 g) and the solution was added to the reactor. A mixture of Solvesso 200 (3.56 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.15 g) was added to the reactor from the initiator tank over 60 minutes. The initiator feed tank was rinsed with Solvesso 200 (1.78 g) and the solution was added to the reactor. The reaction was then held at a constant temperature of 110℃for 60 minutes.

Example 22

A dispersant resin having a random copolymer structure comprising lauryl methacrylate and N-vinyl pyrrolidone monomers is prepared using free radical polymerization chemistry. In a typical preparation, solvesso200 (20.00 g) was charged to a reactor and heated to 120℃under a constant nitrogen atmosphere. A mixture of Solvesso200 (3.60 g) and the free radical initiator tert-amyl 2-ethylhexyl carbonate peroxide (0.44 g) was added dropwise to the reactor from the initiator feed tank over 185 minutes. Five minutes after the start of the addition of the free radical initiator solution, a mixture of lauryl methacrylate (24.50 g) and N-vinylpyrrolidone (10.50 g) was added to the reactor from the monomer feed tank over 180 minutes. After the free radical initiator and monomer feeds were completed, the monomer feed tank was flushed with Solvesso200 (4.80 g) and the solution was added to the reactor. A mixture of Solvesso200 (1.20 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.15 g) was added to the reactor from the initiator tank over 60 minutes. The reaction solution was then maintained at 120℃for 30 minutes. A mixture of Solvesso200 (1.20 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.15 g) was added to the reactor from the initiator tank over 60 minutes. The initiator feed tank was rinsed with Solvesso200 (1.65 g) and the solution was added to the reactor. The reaction was then kept at a constant temperature of 120℃for 60 minutes.

EXAMPLE 23

A dispersant resin having a random copolymer structure comprising stearyl acrylate and N-vinyl pyrrolidone monomers is prepared using free radical polymerization chemistry. In a typical preparation, solvesso 200 (13.15 g) was charged to a reactor and heated to 110℃under a constant nitrogen atmosphere. A mixture of Solvesso 200 (3.56 g) and the free radical initiator t-amyl peroxy-2-ethylhexyl carbonate (0.46 g) was then added dropwise to the reactor from the initiator feed tank over 185 minutes. Five minutes after the start of the addition of the free radical initiator solution, a mixture of stearyl acrylate (26.25 g) and N-vinylpyrrolidone (8.75 g), heated at 45℃to provide compatibility, was added to the reactor from the monomer feed tank over 180 minutes. After the free radical initiator and monomer feeds were completed, the monomer feed tank was flushed with Solvesso 200 (1.56 g) and the solution was added to the reactor. A mixture of Solvesso 200 (3.56 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.15 g) was added to the reactor from the initiator tank over 60 minutes. The initiator feed tank was rinsed with Solvesso 200 (1.78 g) and the solution was added to the reactor. The reaction was then held at a constant temperature of 110℃for 60 minutes.

EXAMPLE 24

A dispersant resin having a random copolymer structure comprising stearyl methacrylate and N-vinyl pyrrolidone monomers is prepared using free radical polymerization chemistry. In a typical preparation, solvesso 200 (23.15 g) was charged to a reactor and heated to 110℃under a constant nitrogen atmosphere. A mixture of Solvesso 200 (3.87 g) and the free radical initiator t-amyl peroxy-2-ethylhexyl carbonate (0.50 g) was added dropwise to the reactor from the initiator feed tank over 185 minutes. Five minutes after the start of the addition of the free radical initiator solution, a mixture of stearyl methacrylate (26.25 g) and N-vinylpyrrolidone (8.75 g) was added to the reactor from the monomer feed tank over 180 minutes. After the free radical initiator and monomer feeds were completed, the monomer feed tank was flushed with Solvesso 200 (3.56 g) and the solution was added to the reactor. A mixture of Solvesso 200 (3.56 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.15 g) was added to the reactor from the initiator tank over 60 minutes. The initiator feed tank was rinsed with Solvesso 200 (1.78 g) and the solution was added to the reactor. The reaction was then held at a constant temperature of 110℃for 60 minutes.

Example 25

A dispersant resin having a random copolymer structure comprising stearyl acrylate and N-vinyl pyrrolidone monomers is prepared using free radical polymerization chemistry. In a typical preparation, n-amyl propionate (18.18 g) was charged to a reactor and heated to 120 ℃ under a constant nitrogen atmosphere. A mixture of n-amyl propionate (3.66 g) and the free radical initiator tert-amyl peroxy-2-ethylhexyl carbonate (0.35 g) was added dropwise to the reactor from the initiator feed tank over 185 minutes. Five minutes after the start of the addition of the free radical initiator solution, a mixture of stearyl acrylate (22.05 g), N-vinylpyrrolidone (9.45 g) and Solvesso 200 (4.50 g) was added to the reactor from the monomer feed tank over 180 minutes. After the free radical initiator and monomer feeds were completed, the monomer feed tank was flushed with n-amyl propionate (1.80 g) and the solution was added to the reactor. A mixture of n-amyl propionate (1.22 g) and t-amyl peroxy-2-ethylhexyl carbonate (0.12 g) was fed from the initiator tank to the reactor over 60 minutes. The initiator feed tank was rinsed with n-amyl propionate (2.25 g) and the solution was added to the reactor. The reaction was then kept at a constant temperature of 120℃for 60 minutes.

EXAMPLE 26

A dispersant resin having a block copolymer structure comprising stearyl acrylate and N-vinyl pyrrolidone monomers is prepared using reversible addition-fragmentation chain transfer (RAFT) polymerization. In a typical preparation, n-pentyl propionate (70.2 g), 2-cyanobutan-2-yl-4-chloro-3, 5-dimethyl-1H-pyrazole-1-dithiocarbonate (BM 1565) (2.0724 g) and stearyl acrylate (100.8 g) were charged to a reactor and heated to 85℃under a constant nitrogen atmosphere (blanket and sparge). A mixture of n-amyl propionate (27.4 g) and the free radical initiator 2,2' -azobis (2-methylbutanenitrile) (0.2769 g) was sparged with nitrogen for 15 minutes and then added dropwise to the reactor over 120 minutes. After the radical initiator feed was completed, the reaction was maintained at a constant temperature of 85 ℃ for 60 minutes. Subsequently, a mixture of N-vinylpyrrolidone (43.2 g) and N-pentyl propionate (21.6 g) was sparged with nitrogen for 15 minutes, and then added dropwise to the reactor over 30 minutes. A mixture of n-amyl propionate (27.4 g) and the free radical initiator 2,2' -azobis (2-methylbutanenitrile) (0.2769 g) was sparged with nitrogen for 15 minutes and then added dropwise to the reactor over 120 minutes. After the radical initiator feed was completed, the reaction was maintained at a constant temperature of 85 ℃ for 150 minutes.

For purposes of the detailed description, it is to be understood that the application contemplates various alternative variations and sequences of steps, unless explicitly stated to the contrary. Moreover, all numbers, such as those representing values, amounts, percentages, ranges, sub-ranges, and fractions, may be considered to be "about" in the beginning, except in any operational instance, or where otherwise indicated, even if the term does not expressly appear. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present application. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Where a closed or open numerical range is described herein, all numbers, values, amounts, percentages, sub-ranges, and fractions within or covered by the numerical range are to be considered as specifically included in and within the original disclosure of the present application as if such numbers, values, amounts, percentages, sub-ranges, and fractions were all expressly written.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

As used herein, "comprising," "including," and similar terms are to be understood in the context of the present application as synonymous with "comprising," and are therefore open-ended and do not exclude the presence of additional unredescribed or unrecited elements, materials, components, or method steps. As used herein, "consisting of … …" is understood in the context of the present application to exclude the presence of any unspecified elements, components or method steps. As used herein, "consisting essentially of … …" is understood in the context of the present application to include the specified elements, materials, components, or method steps, as well as those that do not materially affect the basic and novel characteristics described.

As used herein, the terms "on … …," "onto … …," "applied over … …," "applied to … …," "formed on … …," "deposited on … …," "deposited on … …" refer to forming, covering, depositing or providing thereon but not necessarily in contact with a surface. For example, an electrodepositable coating composition "deposited onto" a substrate does not preclude the presence of one or more other intermediate coatings of the same or different composition located between the electrodepositable coating composition and the substrate.

Although specific embodiments of the invention have been described above for illustrative purposes, it will be evident to those skilled in the art that numerous variations of the details of the invention may be made without departing from the invention as defined in the appended claims.

Claims

1. A dispersion comprising:

An organic solvent;

graphene carbon nanoparticles;

A polymeric dispersant resin comprising an addition polymer comprising a homopolymer, a block (co) polymer, a random (co) polymer, an alternating (co) polymer, a graft (co) polymer, a brush (co) polymer, a star (co) polymer, a telechelic (co) polymer, or a combination thereof.

2. The dispersion of claim 1, wherein the dispersion has an instability index of less than 0.5.

3. The dispersion of claim 1, wherein the grapheme carbon nanoparticles comprise greater than 3 weight percent based on the total weight of the dispersion.

4. A dispersion according to claim 3 wherein the instability index is less than 0.3.

5. The dispersion of claim 1, wherein the polymeric dispersant comprises an addition polymer comprising alkyl (meth) acrylate residues having 8 to 22 carbon atoms in the alkyl group, vinyl heterocyclic amide residues, or a combination thereof.

6. The dispersion of claim 5, wherein the alkyl (meth) acrylate containing 8 to 22 carbon atoms in the alkyl group comprises lauryl methacrylate or stearyl acrylate.

7. The dispersion of claim 5, wherein the vinyl heterocyclic amide comprises vinyl pyrrolidone.

8. The process for preparing the dispersion of claim 1, wherein the grapheme carbon nanoparticles are thermally produced at a temperature of at least 3,500 ℃.

9. The dispersion of claim 1, wherein the grapheme carbon nanoparticles have an average aspect ratio of greater than 3:1 and a raman 2d:g peak ratio of at least 1:1, wherein the grapheme carbon particles are disordered.

10. The dispersion of claim 1, wherein the grapheme carbon nanoparticles are milled grapheme carbon nanoparticles.

11. The dispersion of claim 1, wherein the grapheme carbon particles are turbostratic and have a b.e.t. specific surface area of at least 70 square meters per gram.

12. The dispersion of claim 1, wherein the organic solvent comprises oil, N-methyl-2-pyrrolidone, benzyl alcohol, diethylene glycol monoethyl ester (DE) acetate, and/or triethyl phosphate.

13. The dispersion of claim 12, wherein the organic solvent comprises an oil.

14. The dispersion of claim 12, wherein the organic solvent comprises N-methyl-2-pyrrolidone.

15. The dispersion of claim 1, wherein the weight ratio of grapheme carbon nanoparticles to the dispersant resin is from 0.5:1 to 15:1.

16. A lubricant comprising the dispersion of claim 1 dispersed in a base lubricating oil, wherein the grapheme carbon nanoparticles comprise from 0.05 to 1 weight percent based on the total weight of the lubricant.

17. A lithium ion battery electrode, comprising:

lithium-containing active materials or lithium-reactive particles; and

The dispersion of claim 1.